1. Field of the Invention
This invention relates to liquid aerators and more particularly to a water aerator adapted to be secured to a faucet. Still more specifically, this invention relates to such an aerator having automatic means for controlling the rate of flow of water therethrough so as to compensate for variations in upstream pressure.
In aerators of the type involved here, water under pressure from the faucet enters a diffuser mounted in a cylindrical casing or barrel releasably secured to the faucet. The diffuser breaks up the flow into fine jets which are directed downward into a chamber where they are mixed with air, an aerated bubbly stream being finally discharged through screens located in the discharge end of the barrel and supported by a basket surrounding the mixing chamber. The action of the water jets maintains a subatmospheric pressure in the mixing chamber, thereby drawing air into this chamber by way of a passage defined by the basket and the surrounding barrel.
2. Description of Related Art including Information Disclosed under .sctn..sctn.1.97 to 1.99
It has been proposed heretofore to limit the flow rate into the aerator by means of a flow-restricting disc having a control opening through which the water from the faucet must pass to enter the diffuser. Such a disc has taken the form of a metal plate which snaps into the top of the diffuser as disclosed in U.S. Pat. No. 4,345,719 which issued to my assignee.
A further development has been a pressure-compensating flow controller. This has comprised a circular disc of rubber having a control opening to pass the water flow, the margin of the opening having an upward hub. Under increased upstream pressure, the upward hub is urged radially inward on all sides so that it contracts, and closes down the opening in the plug to reduce flow.
In such developments, the disc has ridden on top of the diffuser and a sealing washer has been required to assure that water does not leak out to the periphery of the diffuser and even through the threads of the barrel where it is secured to the faucet. Further, such aerators, including the separate pressure-compensating flow controllers, suffer from an inability to allow the disc to be assembled into the aerator readily and even automatically, and at the same time, to retain the disc against accidental displacement while allowing easy removal of the disc in cases where a full flow rate is desired.